Pneumatic timing means

ABSTRACT

A pneumatic timing means, which is particularly suitable for use as a delay device or a pulse device at the output end of pneumatic control circuits, especially such pneumatic control circuits which are of the integrated fluidistor type. The pneumatic timing means has very few movable parts, which makes it very reliable, and its exhaust or draining path is very short and has very little flow resistance in the open condition, which makes the exhaustion or draining after each operation of the timing means very quick. The timing means includes first and second diaphragms, preferably integrally formed, for selectively opening and closing the exhaust channel and the output channel, respectively.

United States Patent 1 1 Henningsson [54] PNEUMATIC TIMING MEANS [75]Inventor:

Sweden [73] Assignee: Atlas Copco Aktiebolag, Wacka,

Sweden [22] Filed: Sept. 11, 1970 [21] Appl, No.: 71,491

[58] Field of Search .....137/107, 512.4, 525; 251/15, 251/16, 20, 55,61.1, 51

[56] References Cited UNITED STATES PATENTS 2,529,028 11/1950 Landon..251/61.1 X 2,677,390 5/1954 ..25l/61.1 X 3,010,476 11/1961....137/5I2.4 3,354,902 11 /1967 Obermaier... ...137/525 X 3,543,79212/1970 OKeefe ..25 I/55 X Karl Giista Henningsson, l-landen,'

[ 1 Mar. 27, 1973 Primary Examiner-Martin P. Schwadron AssistantExaminer-David J. Zobkiw Att0rneyFlynn & Frishauf [57] ABSTRACT Apneumatic timing means, which is particularly suitable for use as adelay device or a pulse device at the output end of pneumatic controlcircuits, especially such pneumatic control circuits which are of theintegrated fluidistor type. The pneumatic timing means has very fewmovable parts, which makes it very reliable, and its exhaust ordrainingpath is very short and has very little flow resistance in theopen condition, which makes the exhaustion or draining after eachoperation of the timing means very quick. The timing means includesfirst and second diaphragms, preferably integrally formed, forselectively opening and closing the exhaust channel and the outputchannel, respectively.

15 Claims, 2 Drawing Figures PATENTEDHARZ 7 I873 57 i 7% y p 2 #9 .0 219 h 2 3 m (W h E 6 PNEUMATIC TIMING MEANS The present invention relatesto a timing means for delaying or pulsing a pneumatic signal, whichconsists of a pressure rise.

Previously known delay devices and pulse devices for pneumatic signalshave many components, and thus they are expensive to produce. Besides,the valves in known delay devices and pulse devices have such aconstruction that a relatively high signal pressure is required for areliable and accurate function.

, One object of the present invention is to provide a timing means whicheliminates the deficiencies mentioned above.

Another object of the invention is to provide a simple and reliabletiming means which can be used either as a delay device or as a pulsedevice. Such a timing means offers advantages with regard to productioneconomy and assembly in series (or mass) production of the timingdevice.

Another important object of the invention is to provide a timing meansoffering a markedly shortened quick-exhaust time paired with a reliablefunction at low signal pressures. The novel timing means will thus bedirectly combinable with and connectable to fluidistor circuits and willwork with an air consumption normal for fluidistor operation.

SUMMARY OF THE INVENTION These objects are attained by providingaccording to the invention a pneumatic timing means, comprising an inputchannel, a throttling means and a first cavity, which are so arrangedthat a pneumatic signal, which is the input signal of the timing deviceand which is supplied through the input channel and the throttling meansto the first cavity, produces a delayed pressure rise in the firstcavity in a manner known per se, an output channel and an exhaust valvedisposed in a second cavity for rapid exhausting, each time the inputsignal ceases, of the first cavity via a channel leading from the firstcavity to the exhaust valve characterized in that the exhaust path ofthe first cavity after the exhaust valve comprises a passage leadingfrom the second cavity directly out to the surrounding atmosphere, thatthe exhaust valve is a diaphragm valve communicating at the one facethereof with the input channel and movable with the other face thereofto close or to open the exhaust path, and that another diaphragm isprovided to selectively open and close the output channel responsive tothe pressure rise.

Further objects and advantages will appear from the following detaileddescription of embodiments of the invention taken in conjunction withthe accompanying drawings, in which FIG. 1 shows an embodiment of thetiming device as a delay device and FIG. 2 shows an embodiment of thetiming device as a pulse device.

The timing device comprises a housing or casing 2, in which both thefirst cavity 3, the choke or throttling means 1, the exhaust valve 7 inthe second cavity, the channel 4 which leads to the choke means 1, andthe exhaust channels 5 and 6 which run from the first to the secondcavity and from the second cavity to the environment, respectively, arearranged.

In the embodiments shown the housing 2 is closed by means of a lid or aplate 18, which contains the input channel 16 and the output channel 17.

The choke means 1, which can be of a fixed or an adjustable type, issituated in the wall of the housing 2 and has direct connection to thefirst cavity 3. The choke means 1 and the cavity 3 constitute the timemeasuring means or the timer of the timing device in a manner known perse.

The exhaust channel 5, which leads from the first cavity 3, has itsoutlet in the second cavity in the valve seat of the exhaust valve 7,whereby the outlet of the channel preferably constitutes the valve seatof the exhaust valve in the manner which is shown on the drawings.

The exhaustion of the first cavity 3 goes faster than by previouslyknown timing devices each time the input signal ceases, partly becausethe exhaust valve is a diaphragm valve, which can be constructed withlittle flow resistance in the open condition, partly because the exhaustvalve is situated in the wall of the housing 2 close to the first cavity3, so that the exhaust channel 5 between the first and the second cavityis short, and partly because the exhaustion takes place directly to theenvironment via the exhaustion outlet 6 and not, as by conventionaltiming devices, back to the signal source.

The input channel 16 of the timing device has two openings, of which thefirst opening 12 leads to the channel 4 which runs to the choke means 1and the second opening 11 leads to the second cavity on the control sideof the diaphragm 9 of the exhaust valve 7 for control of the exhaustvalve, so that the exhaust valve 7 is kept closed is the input signal ispresent. The elasticity of the diaphragm 9 causes the exhaust valve tobe in its open condition when no input signal is present.

In the timing device of FIG. 1 the output channel 17 has directconnection with the first cavity via an opening 14.

By the embodiment of FIG. 1 the diaphragm 9 of the exhaust valve 7 isshaped in such a manner that it also serves as a tightening element 10between the housing 2 and the plate 18, whereby the tightening elementcloses a third opening 13 from the input channel and an exhaust outlet15 from the output channel 17, which openings are used in the embodimentwhich Is shown in FIG. 2.

The diaphragm 9 and the tightening or sealing part 10 are, as anexample, made of rubber or some kind of elastic and tightening material.

The plate 18 suitably consists of a fluidistor circuit plate.

The delay device according to FIG. 1 works in the following way. When apneumatic signal in the form of a pressure rise is supplied to the inputchannel 16, the diaphragm 9 in the exhaust valve 7 is affected in such away via the second opening 11 that the exhaust valve blocks the exhaustpath. Via the first opening 12 air then flows from the input channelthrough the channel 4 and the choke means 1 into the first cavity 3.Because of the choke means 1 the pressure rise in the cavity 3 isdelayed in relation to the input signal fed to the input channel 16 in amanner known per se. The delayed pressure rise is the output signal ofthe delay device,

and this output signal further goes through the opening 14 and thechannel 17.

The embodiment of FIG. 2 of the timing device, which as is mentionedabove is a pulse device, is used to generate an output pulse having apredetermined pulse width from an input signal, which can be of acontinuous type or of a pulsed type.

The pulse device is different from the delay device in that a signalinterrupting or breaking valve 20 is arranged in the first cavity 3, sothat the connection between the first cavity 3 and the opening 14 of theoutput channel 17 is closed and that the signal breaking valve 20 canopen and close a signal connection from the input channel 16 to theoutput channel 17. The signal breaking valve 20 is a diaphragm valve,whose valve seat suitably is the plate 18. By absence of an input signalthe diaphragm 23 of the signal breaker is pressed against the valve seatby a resilient means 19, which suitably is a helical spring which isplaced at the control side of the diaphragm, ie the side which does notface the valve seat, as is shown in FIG. 2, whereby a tightening existsaround the opening 14 of the output channel 17 and the signal connectionbetween the input channel and the output channel is broken.

In the embodiment shown in FIG. 2 the diaphragm 23 of the signalbreaking valve and the diaphragm 9 of the exhaust valve are combined inone piece, which furthermore includes the sealing part between thehousing 2 and the plate 18. Thus the change of the timing device from adelay device into a pulse device can be done by exchanging the sealingpart 10 of the delay device with the sealing part 10' of the pulsedevice.

The signal breaker diaphragm 23 of FIG. 2 on its seat side is providedwith a tighteningring 24 and on its control side with a projection 22 oranother reinforcement which opposes deformation because of the spring 19coupled to the portion of the diaphragm which comprises the sealing ring22. The projection 22 has a projecting part 21 which serves as a guidefor the spring 19.

The sealing part 10 has a hole which gives connection between theexhaust opening 15 of the output channel to a bleed or leakagethrottling means 8, which is arranged in the wall of the timing device.

The pulse device according to FIG. 2 works in the following manner. Whenan input signal is fed via the input channel 16, the exhaust valve 7 isclosed in the same manner as in the delay device. At the same time thesignal breaker valve 20 is opened by the signal pressure which isapplied to the seat side of the diaphragm 23 via the third opening 13 ofthe input channel 16, whereby a signal connection is established betweenthe input channel 16 and the output channel 17 via the opening 13, thesignal breaker valve 20 and the opening 14. Because air flows from theinput channel 16, through the opening 12, the channel 4 and the chokemeans 1 into the first cavity 3 a successive equalizing of the pressuredifference between the input signal pressure and the pressure within thecavity 3 takes place. After a certain time, which may be adjustable bymeans of the choke means 1, the pressure difference is so small that theresilient means 19 closes the signal breaker valve 20. In this way anoutput pulse without delay and with substantially the same pulse widthas the delay time of the delay device is achieved.

At the closing instant there occurs an almost stepwise rise of the forceonto the seat side of the diaphragm because the area which is affectedby the input signal pressure decreases with the area which is surroundedby the sealing ring 24 at the signal side of the diaphragm. Therefore itis expedient that the area which is surrounded by he sealing ring 24forms a substantial part of the area of the diaphragm. A ring with alarge diameter also has the advantage that is the resilient means 19causes a moment which acts to twist the diaphragm obliquely in relationto the valve seat or the plate 18, the diaphragm is twisted back intoits right position during the closing.

The output channel 17 is exhausted after the closing of the signalbreaker valve 20 via the bleed throttling means 8, and the first cavity3 is exhausted by means of the exhaust valve 7 in the same manner as inthe delay device, when the input signal ceases.

By virtue of the construction of the timing device according to FIGS. 1and 2, the housing 2 of the timing device can be very simply exchangedwith another component which gives direct signal connection between theinput channel 16 and the output channel 17.

What we claim is:

1. A pneumatic timing means comprising:

an input channel;

a throttling means;

a first cavity;

passage means interconnecting said input channel,

said throttling means and said first cavity in series; an output channelconnected to said first cavity; a second cavity; an exhaust channelconnected to said first and second cavities;

an exhaust passage downstream of said exhaust channel; an exhaust valvedisposed in said second cavity for controlling the communication betweensaid exhaust channel and said exhaust passage, said exhaust valveincluding a first diaphragm forming a partition in said second cavity,said exhaust channel and exhaust passage opening on the same side ofsaid diaphragm, and said exhaust valve further including meanscommunicating the other side of said diaphragm with said input channel,said diaphragm selectively opening and closing said exhaust channel;signal interrupting valve in said first cavity, said signal interruptingvalve including a second diaphragm forming a partition in said firstcavity between said throttling means and said output channel, and springmeans in said first cavity for biasing at least a portion of said seconddiaphragm to a position closing said output channel, the part of saidfirst cavity adjacent said biased second diaphragm portion and on theoutput channel side of said second diaphragm having communication withsaid input channel.

2. A pneumatic timing means according to claim 1 wherein said firstdiaphragm communicates at one face thereof with said input channel andis movable to open or close said exhaust channel with the other facethereof.

3. A pneumatic timing means according to claim 1 wherein said first andsecond diaphragrns are integrally formed as a single diaphragm member.

4. A pneumatic timing means according to claim 3 wherein said input andoutput channels are formed in a plate; said throttling means, firstcavity, second cavity, passage means and exhaust channel are formed in ahousing; and said integrally formed first and second diaphragm membersfurther include means interposed between said housing and said plate forsealingly connecting said housing and plate.

5. A pneumatic timing means according to claim 1 wherein the part ofsaid first cavity around said biased second diaphragm portion and on theoutput channel side of said second diaphragm is in communication withsaid input channel.

6. A pneumatic timing means according to claim 1 wherein said springmeans is a spring interposed between said second diaphragm and a wallportion in said first cavity, and a sealing ring is provided on saidsecond diaphragm on the side thereof opposite to said spring.

7. A pneumatic timing means according to claim 6 wherein said seconddiaphragm includes a projection which is engaged with said spring, saidspring being interposed between said projection and said wall portion insaid first cavity.

8. A pneumatic timing means comprising:

a plate;

an input and an output channel in said plate;

a housing;

a throttling means in said housing;

a first cavity in said housing open to one end portion thereof;

passage means in said housing connecting said throttling means with saidfirst cavity and' with said input channel;

a second cavity in said housing open at said one end portion thereof;

an exhaust channel leading from said first cavity to said second cavity;

an exhaust passage in said housing downstream of said exhaust channeland leading from said second cavity directly out to the surroundingatmosphere;

a diaphragm member sealingly connected between said one end portion ofsaid housing and said plate with a first portion of said diaphragmmember disposed as a partition across said second cavity, said diaphragmmember having a first opening therein for connecting said output channelwith said throttling means, and a second opening therein in the path ofsaid passage means between said input channel and said throttling means;and

a connection between said input channel and said partition for movingsaid partition to close or to open said exhaust channel.

9. A pneumatic timing means according to claim 8 in which said exhaustchannel has a mouth opening in said second cavity which provides a valveseat for said first portion of said diaphragm member.

10. A pneumatic timing means comprising:

a plate; an input and an output channel in said plate; a housathrottling means in said housing; a first cavity in said housing open toone end portion thereof; passage means in said housing connecting saidthrottling means with said first cavity and with said input channel;

a second cavity in said housing open at said one end portion thereof;

an exhaust channel leading from said first cavity to said second cavity;

an exhaust passage in said housing downstream of said exhaust channeland leading from said second cavity directly out to the surroundingatmosphere;

a diaphragm member sealingly connected between said one end portion ofsaid housing and said plate with a first portion of said diaphragmmember disposed as a partition across said second cavity, said diaphragmmember having an opening therein in the path of said passage meansbetween said input channel and said throttling means;

a connection between said input channel and said partition for movingsaid partition to close or to open said exhaust channel; and

signal interrupting valve in said first cavity, said signal interruptingvalve including a second diaphragm forming a partition in said firstcavity between said throttling means and said output channel, and springmeans in said first cavity for biasing at least a portion of said seconddiaphragm to a position closing said output channel, the part of saidfirst cavity adjacent said biased second,

diaphragm portion and on the output channel side of said seconddiaphragm having communication with said input channel.

11. A pneumatic timing means according to claim 10 wherein both saidsecond diaphragm of said exhaust valve and said first portion of saiddiaphragm member are integral parts of said diaphragm member.

12. A pneumatic timing means according to claim 10 further comprising ableed throttling means between said output channel and the surroundingatmosphere.

13. A pneumatic timing means according to claim 10 in which said springmeans is a spring interposed between said second diaphragm and a wallportion in said first cavity, and a sealing ring is provided on the faceof said second diaphragm opposite to said spring.

14. A pneumatic timing means according to claim 13 wherein said seconddiaphragm includes a projection which is engaged with said spring, saidspring being interposed between said projection and said wall portion insaid first cavity.

15. A pneumatic timing means according to claim 13 in which said platearound the inlet of said output channel provides a valve seat for saidsealing ring.

1. A pneumatic timing means comprising: an input channel; a throttlingmeans; a first cavity; passage means interconnecting said input channel,said throttling means and said first cavity in series; an output channelconnected to said first cavity; a second cavity; an exhaust channelconnected to said first and second cavities; an exhaust passagedownstream of said exhaust channel; an exhaust valve disposed in saidsecond cavity for controlling the communication between said exhaustchannel and said exhaust passage, said exhaust valve including a firstdiaphragm forming a partition in said second cavity, said exhaustchannel and exhaust passage opening on the same side of said diaphragm,and said exhaust valve further including means communicating the otherside of said diaphragm with said input channel, said diaphragmselectively opening and closing said exhaust channel; a signalinterrupting valve in said first cavity, said signal interrupting valveincluding a second diaphragm forming a partition in said first cavitybetween said throttling means and said output channel, and spring meansin said first cavity for biasing at least a portion of said seconddiaphragm to a position closing said output channel, the part of saidfirst cavity adjacent said biased second diaphragm portion and on theoutput channel side of said second diaphragm having communication withsaid input channel.
 2. A pneumatic timing means according to claim 1wherein said first diaphragm communicates at one face thereof with saidinput channel and is movable to open or close said exhaust channel withthe other face thereof.
 3. A pneumatic timing means according to claim 1wherein said first and second diaphragms are integrally formed as asingle diaphragm member.
 4. A pneumatic timing means according to claim3 wherein said input and output channels are formed in a plate; saidthrottling means, first cavity, second cavity, passage means and exhaustchannel are formed in a housing; and said integrally formed first andsecond diaphragm members further include means interposed between saidhousing and said plate for sealingly connecting said housing and plate.5. A pneumatic timing means according to claim 1 wherein the part ofsaid first cavity around said biased second diaphragm portion and on theoutput channel side of said second diaphragm is in communication withsaid input channel.
 6. A pneumatic timing means according to claim 1wherein said spring means is a spring interposed between said seconddiaphragm and a wall portion in said first cavity, and a sealing ring isprovided on said second diaphragm on the side thereof opposite to saidspring.
 7. A pneumatic timing means according to claim 6 wherein saidsecond diaphragm includes a projection which is engaged with saidspring, said spring being interposed between said projection and saidwall portion in said first cavity.
 8. A pneumatic timing meanscomprising: a plate; an input and an output channel in said plate; ahousing; a throttling means in said housing; a first cavity in saidhousing open to one end portion thereof; passage means in said housingconnecting said throttling means with said first cavity and with saidinput channel; a second cavity in said housing open at said one endportion thereof; an exhaust channel leading from said first cavity tosaid second cavity; an exhaust passage in said housing downstream ofsaid exhaust channel and leading from said second cavity directly out tothe surrounding atmosphere; a diaphragm member sealingly connectedbetween said one end Portion of said housing and said plate with a firstportion of said diaphragm member disposed as a partition across saidsecond cavity, said diaphragm member having a first opening therein forconnecting said output channel with said throttling means, and a secondopening therein in the path of said passage means between said inputchannel and said throttling means; and a connection between said inputchannel and said partition for moving said partition to close or to opensaid exhaust channel.
 9. A pneumatic timing means according to claim 8in which said exhaust channel has a mouth opening in said second cavitywhich provides a valve seat for said first portion of said diaphragmmember.
 10. A pneumatic timing means comprising: a plate; an input andan output channel in said plate; a housing; a throttling means in saidhousing; a first cavity in said housing open to one end portion thereof;passage means in said housing connecting said throttling means with saidfirst cavity and with said input channel; a second cavity in saidhousing open at said one end portion thereof; an exhaust channel leadingfrom said first cavity to said second cavity; an exhaust passage in saidhousing downstream of said exhaust channel and leading from said secondcavity directly out to the surrounding atmosphere; a diaphragm membersealingly connected between said one end portion of said housing andsaid plate with a first portion of said diaphragm member disposed as apartition across said second cavity, said diaphragm member having anopening therein in the path of said passage means between said inputchannel and said throttling means; a connection between said inputchannel and said partition for moving said partition to close or to opensaid exhaust channel; and a signal interrupting valve in said firstcavity, said signal interrupting valve including a second diaphragmforming a partition in said first cavity between said throttling meansand said output channel, and spring means in said first cavity forbiasing at least a portion of said second diaphragm to a positionclosing said output channel, the part of said first cavity adjacent saidbiased second diaphragm portion and on the output channel side of saidsecond diaphragm having communication with said input channel.
 11. Apneumatic timing means according to claim 10 wherein both said seconddiaphragm of said exhaust valve and said first portion of said diaphragmmember are integral parts of said diaphragm member.
 12. A pneumatictiming means according to claim 10 further comprising a bleed throttlingmeans between said output channel and the surrounding atmosphere.
 13. Apneumatic timing means according to claim 10 in which said spring meansis a spring interposed between said second diaphragm and a wall portionin said first cavity, and a sealing ring is provided on the face of saidsecond diaphragm opposite to said spring.
 14. A pneumatic timing meansaccording to claim 13 wherein said second diaphragm includes aprojection which is engaged with said spring, said spring beinginterposed between said projection and said wall portion in said firstcavity.
 15. A pneumatic timing means according to claim 13 in which saidplate around the inlet of said output channel provides a valve seat forsaid sealing ring.